It is known in the art to coat or encapsulate certain materials to provide a protective barrier to the material and/or to control the release characteristic of the material. A coated material is typically surrounded by a film wherein the film is "adhered" to the composition. An encapsulated material is typically surrounded by a film in the form of a shell or capsule wherein the shell or capsule is not necessarily adhered to the composition.
Topically applied materials such as cosmetics, lotions, fragrances, antiperspirants and deodorants, which contain ingredients that are encapsulated or coated, are known in the art. For example, Japanese Patent No. 86049285 teaches a transparent cosmetic composition comprising a fine powdered mica which is coated with a mixture of a hydrocarbon, a fatty acid, and a silicone oil and then baked at 100.degree. C. to 150.degree. C. for 1 to 5 hours. The coated mica gives a transparent appearance and soft brilliance to skin.
In antiperspirant or deodorant compositions, it is known to encapsulate or coat a deodorant active or a fragrance added to the deodorant or antiperspirant composition however, it is virtually unknown to encapsulate antiperspirant actives.
U.S. Pat. No. 4,803,195 to Holzner teaches a personal care composition having deodorant or antiperspirant activity comprising the deodorant or antiperspirant active and a perfume base wherein the perfume base is either in the form of an aqueous emulsion or in microencapsulated form. The perfume is released upon contact with moisture and can be re-encapsulated in situ.
U.S. Pat. No. 4,818,522 to Ferentchak et al. teaches antiperspirant compositions comprising water-immiscible adjuvants which are encapsulated in thick-walled, hallow, substantially spherical particles of an antiperspirant active. The water immiscible adjuvants include fragrances, antibacterials, antimicrobial or antifungal agents, deodorants or other dermatological preparations. The antiperspirant actives are the encapsulant material therefore Ferentchak et al. does not teach a method for encapsulating antiperspirant actives. The encapsulated water-immiscible adjuvants are prepared by emulsifying the adjuvant in an aqueous solution of the antiperspirant active and spray drying the resulting material.
EP Patent No. 0303461 to Wright teaches antiperspirant and deodorant compositions containing moisture sensitive capsules which in the presence of moisture release sensory agents such as perfumes, skin coolants, emollients, or other benefit agents such as deodorant actives, antiperspirant actives, and anticholinergic actives. The special polymer from which the capsules are formed is preferably a polysaccharide. The method for preparing the capsules comprises preparing an emulsion of water, the special polymer and the sensory or benefit agent and spray drying the emulsion. The only benefit obtained through the encapsulation of the antiperspirant active is believed to be the ability to produce stable alcoholic compositions and release of the agent in the presence of moisture.
U.S. Pat. No. 4,524,062 to Laba et al. teaches an antiperspirant/deodorant stick composition which comprises a powdered antiperspirant active, a coating material for the antiperspirant active, a deodorant and a cologne stick base. The coating material is typically a glycol stearate and the coated antiperspirant active is achieved by blending the antiperspirant active and the glycol stearate at a temperature at which the glycol stearate is a liquid. U.S. Pat. No. 4,524,062 does not teach a process for obtaining the antiperspirant active in an encapsulated form and there is no evidence to show that the antiperspirant active is even coated and not merely suspended in the glycol stearate.
It is an object of this invention to show encapsulated aluminum halohydrate, aluminum nitrohydrate compositions and mixtures thereof.
It is further an object of this invention to show a method for producing the encapsulated aluminum halohydrate and aluminum nitrohydrate compositions.
It is further an object of this invention to show a method for producing encapsulated aluminum halohydrate and aluminum nitrohydrate compositions of a controlled particle size and shape.
It is further an object of this invention to show deodorant and antiperspirant compositions comprising the encapsulated aluminum salts.